Technical Field
The present invention relates to a kerf structure for a snow tire, and more particularly, to a kerf structure for a snow tire, wherein unit structures having central semi-sphere holes and protrusions formed in opposite directions by polygonal shapes around the semi-sphere holes are continuously formed, thereby more efficiently exhibiting an edge effect of the kerf during rotation on snow-covered roads, as well as accomplishing a friction force from a collapse of small blocks of a tread portion partitioned by the kerfs at an optimum level.
Description of the Related Art
Typically, pluralities of horizontal and longitudinal grooves are formed on the tread portion of a tire and kerfs of small grooves are formed on the block partitioned by the grooves so as to adjust the rigidity of the block.
In the case of a conventional snow tire, driving and braking performances on snow-covered roads are secured by the edge effect of the kerfs during rotation on snow-covered roads. However, the kerf adapted for this edge effect reduces the rigidity of the rubber tread block and degrades the performance of a snow tire on dry roads. FIG. 1 shows the general shape of such a conventional 2D kerf for a snow tire.
Hence, although a 3D kerf has been developed to maintain the rigidity of a tread block due to the constraints of a kerf in a vertical direction on the tire surface, in actuality, it has been difficult to maintain the optimal level of rigidity. FIG. 2 is a photograph showing that in such a snow tire having a conventional kerf, small blocks of a tread portion partitioned by the kerf are collapsed when the tire is in motion. As can be seen in FIG. 2, in a conventional kerf for a snow tire, either an excessively collapsed state A of a block occurs, or a phenomenon where the leading portion of the tire is entangled occurs, thereby decreasing a friction force caused from road surface.
The description provided above as a related art of the present invention is just for helping in understanding the background of the present invention and should not be construed as being included in the related art known by those skilled in the art.